{smcl}
{* 8june2004}{...}
{hline}
help for {hi:twoway_estfit}{right:manual: }
{hline}

{* index lines, adding}{...}
{* index adding lines}{...}
{* index adding fits, see fits, adding}{...}
{* index fits, adding}{...}
{title:Twoway prediction plots}

{p 8 60 2}
{cmdab:tw:oway}
{cmd:estfit}
{it:yvar} {it:xvar}
[{it:weight}]
[{cmd:if} {it:exp}]
[{cmd:in} {it:range}]
[{cmd:,}
{it:estcmd(command name)}
{it:lfit_options}]

{p 4 4 2}
{cmdab:estc:md:(}{it:estimation command name}{cmd:)} specifies the name of the Stata estimation command 
         to use for fitting the model and creating the prediction line

{p 4 4 2}
{it:lfit_options} are any options allowed by {help twoway_lfit}.  The {cmd:estopts} and {cmd:predopts} now 
apply to whatever command is specified in {cmd:estcmd}


{title:Description}

{p 4 4 2}
{cmd:twoway} {cmd:estfit} is a more flexible alternative to (cmd: lfit} --
it calculates and plots the prediction line from fitting {it:yvar} on {it:xvar} 
using the model specified in {cmd:estcmd}.  For more detailed syntax and help see {help twoway_lfit}, 

{p 4 4 2}
{cmd: estfit} only differs from {cmd: lfit} because it allows you to specify a 
different estimator rather than {cmd: regress} that is built into {cmd: lfit}.


{title:Options}

{p 4 8 2}
{cmd:estcmd(}{it:estimation command name}{cmd:)}
    specifies the name of the command to be run to estimate the 
    model from which the line will be predicted.  Choices include any 
    Stata command that can be run using the the y and x vars.  Common
    applications could include {cmd:rreg} or {cmd:qreg} for more robust linear fits than
    {cmd: lfit} provides, but can be any command that works with 
    {cmd: predict} such as {cmd:logit}, {cmd:probit}, {cmd:poisson}, {cmd: glm}, or
    even user-written non-linear or maximum likelihood models.

{p 4 8 2}
{cmd:estopts(}{it:model_options}{cmd:)}
    as in {cmd: lfit}, specifies options to be passed along to {cmd:estcmd} to estimate the 
    model.

{p 4 8 2}
{cmd:predopts(}{it:predict_options}{cmd:)}
    as in {cmd: lfit}, specifies options to be passed along to {cmd:predict} to
    obtain the predictions after estimation by {cmd:estcmd}.


{title:Typical use}

{p 4 4 2}
{cmd:twoway} {cmd:estfit}, like {cmd: lfit}, is primarily used in conjunction 
with other {cmd:twoway} plottypes, such as

	{cmd:. sysuse auto, clear}

	{cmd:. scatter mpg weight || estfit mpg weight, estcmd(qreg) }

{p 4 4 2}
Results are the same as typing

	{cmd}. qreg mpg weight
	. predict fitted
	. scatter mpg weight || line fitted weight{txt}


{title:Also see}

    Manual:  {hi:[G] graph twoway lfit}

{p 4 13 2}
Online:  help for
{help twoway_lfit};
{help twoway_qfit},
{help twoway_fpfit},
{help twoway_mband},
{help twoway_mspline};
{help twoway_lfitci};
{p_end}